What are the tax free benefits/reimbursements in Germany?

Some common tax-free benefits/reimbursements for employees:

• Travel costs: Besides the usual reimbursement of travel costs (e.g. hotel or flight costs) the Client can reimburse the employee for travelling with the employee's own car. In this case, a rate of €0.30 per kilometre can be paid.
• Surcharges (for work on Sundays, public holidays and during nights): In this case, the employer can pay up to 50% extra which is not subject to tax.
• Vouchers for goods or income not provided in the form of money: The Client can offer the employee a voucher of up to €44 per month. A common use case for vouchers is for petrol. If more than €44 is given to the employee within the same month, all benefits will become taxable.
• Training and education: Costs for job-related education and training are usually tax free.
• Relocation expenses: Costs for work-related relocations can be reimbursed to a certain extent (maximum amounts, according to the Bundesumzugskostengesetz).